1. Field of the Invention
The present invention relates to a liquid ejection head configured to heat a liquid by a heat-generating element and to eject the liquid through an ejection port, and an inkjet printing apparatus.
2. Description of the Related Art
The inkjet printing apparatus includes a thermal inkjet system in which ink is heated by driving a heat-generating element arranged inside a liquid ejection head and bubbles are generated within the ink, thereby ink droplets being ejected through an ejection port.
In the liquid ejection head in the inkjet printing apparatus of thermal inkjet system, in the case where bubbles are generated by driving the heat-generating element in order to eject ink droplets, a backflow of ink may be caused inside the ink flow passage of the liquid ejection head due to generation of bubbles. In the case where the backflow of ink is caused, the pressure increased by generation of bubbles is reduced inside the ink flow passage and there is a possibility that the efficiency in ejection of ink droplets is lowered. Therefore, there is a possibility that power required for driving the heat-generating element is increased and energy consumption is increased.
The liquid ejection head in which blocks are arranged around the heat-generating element in order to suppress such a backflow is disclosed in Japanese Patent Laid-Open No. 2006-007780. Since blocks are arranged around the heat-generating element, the backflow of ink caused by generation of bubbles in ejection of ink is suppressed to be small. Therefore, in driving the heat-generating element, kinetic energy is efficiently given to stored ink and it is possible to eject ink droplets efficiently and to reduce the consumption amount of energy.
However, in Japanese Patent Laid-Open No. 2006-007780, the position of the block arranged around the heat-generating element in the liquid ejection head is not specified. Therefore, depending on the position of the block arranged around the heat-generating element, there is a possibility that bubbles generated by driving the heat-generating element are not used efficiently for ejection of ink. Due to this, there is a possibility that it is necessary to generate a larger amount of heat by the heat-generating element in order to eject ink, and thus the amount of power consumption increases and the running cost rises. Furthermore, the size of the heat-generating element used for ejection of ink is increased, and thus there is a possibility that the liquid ejection head becomes large and at the same time, the manufacturing cost of the liquid ejection head rises.